Brussels - The North Atlantic Treaty Organization is looking for states around the Horn of Africa to take charge of Somali pirates captured at sea by alliance warships, NATO's secretary general said Thursday after talks with defence ministers.

The European Union in March agreed a prisoner hand-over scheme with Kenya, and "NATO is working along the same lines but we are not there yet," NATO Secretary General Jaap de Hoop Scheffer told journalists in Brussels.

NATO already has an anti-piracy mission in Somali waters, but it has been dogged by legal difficulties: Each warship acts according to its national legislation, and some legal systems have no provisions for dealing with pirates apprehended in international waters.

That led to a situation on April 18 in which three NATO warships and two helicopters caught seven pirates after an all-night chase, but then had to release them "according to national regulations."

The current mission is set to end on June 28. Defence ministers on Thursday agreed in principle to launch a longer-term mission, but failed to resolve the question of whether it should use NATO vessels already in the area or be custom-built.

"Meeting this challenge, also for NATO, requires all hands on deck. ... As far as the hardware is concerned, there is more homework to do," de Hoop Scheffer said.

A legal agreement is "not an absolute pre-condition" for such a mission, but it would be a "great help," he said.(dpa)